The present invention relates to a bicycle for children, particularly relates to a bicycle with bevel gear drive for children.
At present, in the field of bicycles for children, the wheel is usually driven by a chain drive; due to naivete and curiosity, children are likely to put their hands into sprockets, chain wheels or other driving members, causing injury. In addition, as sprockets and other driving members rely on lubricant for lubrication, the greasy dirt will easily stain clothes during use.
More recently, there are chain-free bicycles. For instance, Chinese patent No. 99224792.1 discloses an improved chain-free bicycle driving structure, which is a common chain-free drive single axle structure with a foot brake on the rear wheel axle. However conventional bicycles with chain-free driving devices also have the problems in that the bevel gears need lubricant for lubrication, and that the lubricant will easily stain clothes and other articles, and that the driving components (particularly bevel gears at rear wheel axle portion) have to be specially custom-made and lack interchangeability with bicycle components of other kinds. Since the drive bevel gears of bicycles of this kind are all arranged inside the intermediate axle, their maintenance is relatively difficult and they need relatively larger torque to be driven, while children have less foot strength and thus need greater effort to pedal and there is no demand on riding speed for children""s bicycles.
In addition, the U.S. Pat. No. 5,299,819 also discloses a chain-free drive bicycle, in which the problems also exist in that it needs lubricant for lubrication, easily stains clothes, and is not adapted to children, who have less foot strength.
The object of the present invention is to provide a bicycle which is clean and safe for use, convenient for maintenance, of good interchangeability of drive parts, and adapted to children""s use.
The basic concept of the present invention is to use bevel gear drive to replace chain drive. Since children have less foot strength, there is less demand on riding speed for children""s bicycle; under the same torque, to increase the diameter of bevel gears can reduce the demand for chileren foot strength and bevel gear sustaining ability, and the bevel gears can use high-strength nylon to replace metallic parts; at the same time, the lubricating function possessed by high-strength nylon itself is utilized to lower noise and prevent lubricant from staining clothes. The drive components have good interchangeability with existing drive components, thereby facilitating manufacture and maintenance.
In order to arrive at the above-mentioned inventive objectives, the present invention adopts a technical scheme in which a bicycle for children with a bevel gear driving device comprises a bicycle body, a wheel, a handlebar, a driving device, and a braking device; the pedal intermediate axle of the driving device is connected with drive bevel gear, the drive bevel gear meshes with a bevel gear of the intermediate axle part on the drive axle, a bevel gear on the rear drive axle part meshes with a bevel gear on the rear wheel axle, outside the meshing portion of each bevel gear is provided a protecting hood, which is made of high-strength nylon, the drive bevel gear is provided outside the pedal intermediate axle, the rear wheel axle has a foot braking device. Inside the bevel gear on said rear wheel axle is provided an insert made of rigid material, and there are positioning protrusions on the insert. On the rear wheel axle spindle are provided concave slots corresponding to those protrusions. Between the insert and bevel gear inner wall is formed a boss shape. Said insert is fixed by a spring ring and screw thread at its outside.
The advantages of the present invention are that the driving device adopts a chain-free drive, that at the mesh portion of each bevel gear is provided a hood, that the children""s bicycle can prevent children from putting their hands into the driving device to ensure safer use; since every bevel gear is made by using high-strength nylon and nylon itself has good lubricating function needless of adding lubricant, it can lower noise, prevent clothes staining, and allow cleaner use; as the drive bevel gear is provided outside the pedal intermediate axle, the drive bevel gear can be made larger in diameter, and the rear wheel axle has a foot braking device, so as to adapt to children""s characteristic of less foot strength and at the same time allow the strength of nylon material to satisfy design requirement. Since inside the bevel gear on the rear wheel axle is provided an insert made of rigid material, the rear wheel axle of a child""s bicycle can be retrofitted directly from existing chain type rear wheel with foot brake to allow the driving device to have a better interchangeability. There are positioning protrusions on the insert, and corresponding concave slots on the rear wheel axle nave, and between the insert and bevel gear inner wall is formed a boss shape to make the rear wheel axle part more convenient both to installation and maintenance.